The invention relates to a gas burner in general and, more particularly, to a gas burner having a mixing pipe and an impeller disk.
In known gas burners of this kind, a corrugated disk is provided having a central mounting opening and several passage openings located on an inner ring line for a gas mixture supplied from below. The corrugated disk also has an outer edge area showing waves or profilings for forming radially directed outlet openings for the gas. Under the corrugated disk, an apertured disk or a sieve is disposed for preventing the flame from going back into the mixing pipe, and above the corrugated disk, a cover disk is located which covers the upper edges of the waves or profilings for forming radial flow channels, as well as a cover whose rim is somewhat drawn to the inside downwardly and protrudes the corrugated disk. This arrangement consisting of several individual components is fixed to a burner head by means of a central disk. The corrugated disk therein creates flames directed radially to the outside and forming a radial flame circle depending on the burner size and the set gas pressure.
Such a burner has to meet various demands which partly are contradictory. The burner has to permit a so-called continuous ignition, i.e. during lighting one single flame coming out of the marginal opening must be capable of igniting the gas beam coming from the neighboring opening so that the burner is ignited all over the circle in short time and no un-used gas leaves. Continuous ignition, however, only is possible if the gas beam does not exit in too much of a focused manner and is somewhat swirled at the rim of the cover. This, however, once causes an undesired disturbance of the once ignited flame by the latter being diverted in direction of the cooking trough and said cooking trough being heated thereby.
The burner furthermore must be backfire-proof, ie. also even in case of low set flame the latter may not go back into the mixing pipe or continue burning in the burner head, since otherwise the burner might be destroyed after a short time. The already mentioned sieve or the punched disk, respectively, serves for safety against backfire.
For safety reasons it is necessary and prescribed in pertinent regulations that the created burning gases should be as free as possible of unburned gas and carbon monoxide. This primarily is done by adding an exactly dosed admixture of air into the mixing pipe in dependance on the governor position and by guiding the gas in the burner.
For reasons of easy handling a burner also should produce as little noise as possible. For this purpose an additional plate by which the noise is eliminated to a large degree is provided for positioning above the sieve plate.
Finally a gas burner should also have an efficiency as high as possible, this usually meaning the relation of the amount of energy supplied with the gas with respect to the amount of energy taken by the vessel to be heated. A given minimum efficiency is defined in the pertinent admission regulations. In the European standard EN 30 the minimum efficiency is 52 percent related to the heating power Ho.